Elapsed time indicator



Oct. 12, 1948. SPRINGER 2,451,250

I ELAPSED TIME INDICATOR Filed NOV. 22, 1946 29 I IHVQWCQT hamsSpringer:

His A't'torne g.

Patented Oct. 12, 1948 UNI T ED S TATES PAT EN T OFFICE .1 EL'APSED TIMEINDICATOR Application November 22, 1946, Serial No. 711,682

-Claims.

.My invention relates toelapsed timeindicators such as willbe usefulintiming'predeterminedad justabletime intervals such, for example, ascooking or photographic developing operations and the ike.

Its object is to .provide a simplegrugged'inexpensive timer of thistypewhich is adjustable as to the timed interval, including both initialtime settings and plus or minus changes-thereof during the timeinterval, which'gives an accurate indication of the timesetting andthetime remaining in the time intervalat all times during such interval,and which produces an alarm at the end of the time-interval. A furtherobject of the invention is to provide an-interval timer of the characterdescribed in which all of the operations incident to setting,timing,alarm-operation and alarm shutoff are performedby'turning asingleshaft in opposite directions either by a timer motor or manually.

The features ofmy invention-Which are believed to be novel andpatentable will be-pointed out in the claims appended! hereto. For abetter understanding of my invention, reference is made inthe followingdescription to the accompanying-drawing in which Figsl'representsa faceview' of my elapsed timer and Fig.2 aside sectional view thereof takenon line '2-2- of Fig. 1. Fig. Sis a front view but with :the glasscover, holding-rim, and most of the front stationary indicator dialremoved. Fig. 4 is a View taken on lineZ4-4, -Fig' 1, of an upperportionof thelstructure to help in showing the disposition ofapart 40usedfor guiding a movable indicator-34 .through'a slot. 36 ina frontdial I3. Figs. 5, 6,.and 7 are front viewswith the greater portion ofthefront indicator partsbroken away to show the drivingmechanism and anoperating cam in differentpositions, Fig.6 represents a full alarm offposition Fig..6 atime interval setting position, and Fig. 7 analarmionposition.

Referring first primarlylto Fig. 1, :the :device includes aself-starting synchronous clockmotor having a two-polemagnetic fieldstructure I with an energizingcoili .onits yoke and ianarmature, notshown, butcontained within a vreduceddiameter portion 3 ofa casing 14containing speed reducing gearing between the motorarmatureand aterminal drive shafthavingthereona gear Spinion- 5. The pole pieces-ofthe field structure e'mbrace the portion? of'the casing and areseparated from the rotor onlybythe thin-shell of the nonmagnetic casing.Amotorstructure ofthis character-is shown indet-ail in-United 'statesPatent No.'1,495',936. The motor is""riveted or 'otherwise ber 1 tovibrate insynchronism with the flux pulsations when such armature isfree to'do'so.

Its right-hand'free'endas best shown in Figs. -2, l,

and 6, may then strikeagainst amagnetic-bu shing 9 secured to-thefieldcore 2 to produce an audible alarm. however, be held'againstvibration and thus re- The armature member 1 may,

main silent by-reason of an extension 10 thereof resting againstthe-high parts of a cam II as shown in Figs. 5 and 6 and as-will beexplained more in detail later.

Spaced'tothe front of -andsecured to-platefi is another plate-l2 whichforms the rear-housing portion of the-elapsed timer dial structurewhichincludes a stationaryindicator dial l'3,a=glass front cover H and anouter-'bezel-ring -l5-which secures-the glass cover and'dial plate-l3'to housing plate l2. 'Thedial l3 is space'd to the front ofhousing-plate-ll-by reason'of spacing lugs l6 pressed out tothe=frontfrom plate [2. Likewise theglass cover! 4- is spaced slightlytothe-front of stationary dial-plate l-3 by reason of -a-spacing ring llpreferably made of'a slightly compressible gasket material. Lugs -I8extending forwardfrom plate 12 embrace dial= plate -'l-3 at two-or morepoints about its periphery to help position and hold it in-place,andlugs -l-9 extending tothe-rear from the outer bezel-ring arebent-around to the rear of--spacing lugs l6 of plate 42 m secure thebezel ring H5 in place,--therebyholdingthelglass cover against gasket 11and the-gasket against dial plate 43.

The space between plates =6 and 42 is occupied lay-reduction gearingbetween the terminal pinion '5 of the motorunit' and ashaft ZShaVingbearings in plates'G andl'Z and extending forward through openings atthe centers of dial .plate-ls'and glass cover- M and having an operatingthumb-piece -2 l securedon its front end and accessible at the front ofthe timer. "The-gear reduction just referred=to includes theygears 22,23, 24, 2-5 and a mutilated gear26 on shaft 2:? best shown'iniFigffiThis geartrain also includes aslipfriction. clutch indicatedjatii1,1Figfl 5,",between; gears 24 and"215.

Secured on the rear "of "shaffiflisthe "cam "I l which cooperates withthe alarm armature as previously mentioned. The cam H with its camfollower l9 not only has the usual cam actions but also acts as atwo-way stop to limit the travel of the cam in opposite directions. Thisis by reason of the short radial projection 28 on the cam periphery. Thegreater length of the came periphery is occupied by the raised surface23 on which the cam follower l rides to hold the alarm armature! raisedand prevents the same from vibration during a timing interval. Therelatively short depression 33 in the cam when opposite the cam followerIn as represented in Fig. 7 allows the armature l to Vibrate freely andthe alarm to sound at the end of a timing interval, The notch 3| in thecam surface is for the purpose of receiving the cam follower at thetermination of a timing interval after the alarm has been silencedmanually, as shown in Fig. 5. In this position the cam follower vibratoris raised sufficiently to prevent alarm operation, and the notch 31prevents easy accidental turning of the cam clockwise from thisposition, while the stop prevents counterclockwise rotation of the cambeyond this position.

Also secured to shaft 20 is an indicator member having a hub part 32, aradial spider part 33, and a C-shaped sector part 34, which extendsaround to the right from the radial spider part 33 nearly during theremainder of the timing interval to show the time remaining in theinterval. The indicator sector 34 and its spider 33 are of relativelythin, somewhat flexible, material to permit the greater portion of thesector 34 to pass through a radial slit 36 in the dial plate l3 so thatthe greater portion of sector 34 may lie in front or all completelybehind the dial plate depending on the rotary position of the indicator34. That portion which is in front of the dial plate lies loosely in atrack or depression 31 in the front of dial plate 13. This depressionbegins at the slit 36 andextends around the dial plate in a clockwisedirection about 310 degrees to the point 33 opposite the upper end ofthe time graduated scale 35. The depression gradually becomes shallowerfrom the slit 36 to point 38, is concentric with shaft 20, and is of aradial width slightly greater than the radial width of indicator sector34 so as to accommodate that portion of sector 34 which is exposed infront of the dial plate with the front surface of the sectorapproximately flush with the raised or time graduated portion of thedial plate. Also the front surface of the indicator member or at leastthe sector 34 part thereof has a color which contrasts with the frontsurface of the dial plate. Thus the dial plate may be polished abrasswith black time graduations, and the front surface of the indicator maybe enameled in red.

.To assure that the free end 39 of the colored indicator sector 34 willalways pass through slit 33 when the sector is turned clockwise from thecompletely unexposed position to a partially exposed position, a guidemember 40 is preferably provided. This guide member is secured to thefront side of plate [2 and has a short sector spaced from plate [2 onthe same radius as sector 34 and which extends in a clockwise directiona short distance through the slit 36 as best shown in Figs. 1, 2, 3, and4. It is to be noted that the slit 36 is out in dial plate l2 at thecounterclockwise end of the depressed sector portion 3'! thereof orbetween a raised and depressed portion of plate [2 so that the slit inefiec't faces in a clockwise direction from behind to the front of dialplate 12. The guide 40 rests tight against the depressed surface portionof this slit and has the effect of continuing the depressed trackportion 3! through the slit in a counterclockwise direction. When thecolored indicator sector 34 is rotated clockwise from the fullyconcealed position, such as represented in Fig. 3, the free end 39thereof is guided through the slot 36 by the guide 40. The spider end ofsect-or 34 moves behind the guide 46 when the sector is rotatedcounterclockwise to its extreme counterclockwise po-- sition and thatportion of guide 40 which extends through slit 36 hides any portion ofthe colored sector 34 behind the guide which might otherwise be seenthrough the slit (see Fig. 4). There is a slight spiral shape to thesector 34 so that its free end 39 is displacedslightly toward the frontof the device as compared to the spider end thereof. This spiral shapeconforms generally to the corresponding change in depth of the depressedtrack 31 in the dial plate. The design is such that the shaft 23 withthe cam I l and indicator 34 thereon may be easily rotated by the timermotor I through th gear train and friction clutch 21, or manually by thethumb-piece 2| with clutch 21 slipping when gears 25 and 26 are in mesh.The construction is such as to provide a compact, closely spaced, andrelatively thin dial assembly such as is shown in Fig. 2.

The relative rotary positions of the cam H, the mutilated gear 26, andthe indicator sector 34 on shaft 20, and the relative rotary positionsof these parts with respect to the parts with which they cooperate aresuch as to insure their proper sequence of opera-tion in accomplishingthe results desired.

InFig. 5 the cam follower ID is shown in the notch 3| and against stopprojection 28 of cam II. This is the full or manually oif position ofthe device. The vibrator arm 1 is lifted and does not vibrate. Themutilated portion of gear 26 is opposite gear 25 and there is no drivingconnection between the timer motor and cam shaft 20. The coloredindicator sector 34' is completely hidden behind the time indicatingdial with its free end 39 in an upper center position as represented inFig. 5. Thus in this position the alarm is turned off, the timerindicator is disconnected from the motor and the time indication iszero. This is the normal condition of the apparatus when not in use. Themotor may be energized or not as desired.

To make use of the device to time an interval, the motor is energized.if deenergized. The thumb-piece 2| is turned clockwise, rotating theparts attached thereto accordingly. Cam follower l0 rides out of notch3| into the depression 30. This may cause the alarm to sound momentarilyif "the manual setting operation is slow and cor responds to thepositioniiofl the parts shown in Fig. 7. However, it is assumed thatinsuch a setting operation the manual clockwise rotation will besufficiently rapid that the sounding of the alarm will hardly benoticeable, if it is noticeable at all. The cam follower'is then pushedup as it rides out of the depression 30 onto the raised the free end ofindicator sector 34 appears through slot-36, andthe'counterclockwise endof the toothed portionof mutilated gear 26 meshes with its driving gear25. This manual clockwise setting operation is continued until'thefree'end 2c of colored sector 84 is opposite the timegradua'ti'ondesired, say for example 40 on the graduated scale '35. In such portionof the setting operation the gear 25 is'driven manually 'by gear '26 inthe opposite direction-to thatwhich it-is driven by the timing motor,and the clutchat Z'Islips.

The device is now set for a timing interval of 40 which may be secondsor minutes or any othertime units, depending onthe gearreduction ratioused. The gearing represented assumes that the terminal pinion'fi of themotor operatesat 316 revolutionsper minute and that the time dial of thedevice'is graduated-in minutes. The thumb-piece 2| is nowreleased andthe timer motor drives the colored sector 34 counterclockwise at a ratesuch that it will disappear through slot 35 in exactly 40 minutes. It isto'be noted that if at any time during the 40-minute time interval it isdesired to reset the device for a shorter or longer timing interval, itcan be done. Also, that the free end of the colored sector 34 at alltimes indicates on the graduated scale the time remaining in the timeinterval and'that'the exposed length of the sector is likewiseameasureof the time remaining in the time interval and can be seen from aconsiderable distance.

At the end of the 40 minute'interval cam follower ill drops intodepression 31],so11nding the alarm, and simultaneouslythe clockwise endof the gear sector ofgear 26 is disengaged'with. gear 25. The devicewill stay in this condition'until reset or turned full oif by hand. Thealarm can be silenced by turning thumb-piece 2| counterclockwise toraise cam follower ifi'intonotch 3!. The stop projection 23 incooperationwith the cam follower prevents the manual turning of theshaft 28 too far in either direction and can have a peripheral length aslong as desired :for this purpose. Figs. 1 and 2 indicatethe coloredsector 3 to be in approximately the full off'position. Fig. 6 representsapproximately a 54-minute time time setting with the free end 29 ofcolored sector 34 exposed opposite the 54-minute graduation. On thefront of the time dial just to the inside of the indicatortrack fl thereare preferably arrows with the notations On and Off to indicate thedirections in which the knob 2! should be turned for turning the timeron as in a time setting operation and for turningthe timer off tosilence the alarm at the end of a timing operation. It is noted thattheteeth of gear 26 are omitted over that section which is oppositerdrivinggear 25 when the cam I l is between thepositions shown in Figs.and 7 where only manual operation of the timer shaft 20 is desired.

If desired, a remote electrically actuated alarm maybe sounded at theend of'a time interval and an arrangementthe motor is shut off by -knob2 l with the shutting oif-ofthe alarm'and-is' turned on again when thetimer issetfor a timingoperation. This assures that the motor will beenergized only during timing andalarm sounding operations, without thenecessity of-any attention by the user of the device exceptthat incidentto the manual turningofknobz l 'for theother purposes described.

'What I claim as new and desire tosecure by Letters Patent ofthe'UnitedSta-tes is:

tween said motor and shaftlincluding aslip friction clutch and amutilated gear through which said shaft may be driven in one directionan amount limited'to less than one-complete'revolution by reason of themutilated gear, manual means for turning Jsaid shaftin eitherdir-ection, such'manualturning being permitted when -the shaft is indriving relation with-the timermotor byreason of the slipping of.saidclutch, an alarm, a cam on said shaft, .a cam follower bearingagainst said cam for controlling the operation of said alarm,anindicator on :said shaft, agraduated time dial on which said indicatorindicates to show the rotary position of said shaft, thecam surface ofsaidrcam having along raised surface, a short depressedisurface. and-ashort-raised surface extending about the "cam-in the'order named in thedirection opposite to that in which the cam is adapted to bedriven bythe timer motor,and a'stop projection on the cam between the long andshort raisedsurfaces whichprevents movement of such stop projection pastthe cam follower in either-direction, saidttimer motor being-in drivingconnection with said'ro'tar'y shaft'onlywhen the cam follower-is restingon the long raised portion of said cam, said indicator indicatingatthe-zero 'end ofsaid scale whenthe cam follower is in the-shortdepressed-portion of said cam and at the other end of the graduatedscale when the cam follower is on thelong raised portion of said camand'adjacent the stop projection and said cam'follower' permitting thealarm to sound only whenin the short depressed-portion of said cam.

2. An internal timer com prising'a timer motor, an alarm, a cam followerfor controlling said alarm, a graduated time dial, a rotaryshaft, 'adriving connection between. said-timer motor and shaft includinga'mutilatedgear on said shaft and a slip friction clutchga cam on saidshaft for controlling the operation of the "alarm through thecamfollower, an indicatoron said shaft cooperating with said time dialto indicate the time setting of said timer, a man'ual thumbpiece forrotating said :shaft for the purpose of setting the timer and shuttingoff the-alarm, and

stop means for limiting the rotation 'of said shaft to slightly lessthan a complete revolution, the arrangement and relative:ro'taryrelation of the parts secured to'therotary shaft'being suchthatthe timermotor may drive the shaft onl'y-in'one directionfromastopp'edmosition where the indicator gives a maximum timeindication onsaid scale to an alarm sounding position Where the indicator indicateszero on said scale whereat the motor is disconnected from drivingrelation with said shaft by reason of the mutilated gear and the camallows the cam follower to move to the alarm sounding position to soundthe alarm only in such rotary position, said shaft having a furtherlimited range of rotary movement between the alarm sounding position andthe other stop- 7 ped position during which it is disconnected from thetimer motor and over which it may be moved manually from alarm soundingposition to shut off the alarm.

3. An elapsed time indicator comprising a stationary dial having acircular time graduated scale thereon extending over a substantialportion of a circle and having a radial slit therein in radial alignmentwith the zero time graduation of such scale, an indicator rotativelymounted behind the dial on an axis concentric with the circular timescale, said indicator having a radial spider portion and a sector-shapedindicator portion of a color contrasting with said dial, the sectorportion being secured to the spider portion at one end only and with itsfree end extending in an upscale direction concentric with the axis ofrotation on a radius to permit it to pass through said radial slit whenthe indicator is rotated, said indicator having a range of rotation froma position where it is completely hidden behind the dial to a positionwhere it is largely exposed with its free end in radial alignment withthe upper end of said time scale, means for guiding said sector throughthe slit when rotated, a timer motor, a

drive connection between said motor and indicator including a slipfriction clutch and a mutilated gear by means of which said motor maydrive said sector in a downscale direction only between maximum and zerotime indication at a rate corresponding to the time graduations, manualmeans for rotating said sector in either direction over the same rangeand over an additional range of movement where the sector is hiddenbehind the dial, and an alarm actuated in response to the arrival ofsaid indicator at a zero time indicating position and cut off by movement of said indicator in either direction from said last-mentionedposition.

4. An elapsed time indicator comprising a stationary dial having acircular time graduated scale thereon extending over a substantialportion of a circle and having a radial slit therein in radial alignmentwith the zero time graduation of such scale, an indicator rotativelymounted behind the dial on an axis concentric with the circular timescale, said indicator having a radial spider portion and a sector-shapedindicator portion of a color contrasting with said dial, the sectorportion being secured to the spider portion at one end only and with itsfree end extending in an upscale direction concentric with the axis ofrota tion on a radius to permit it to pass through said radial slit whenthe indicator is rotated, said indicator having a range of rotation froma position where it is completely hidden behind the dial to apositionwhere it is largely exposed with its free end in radial alignment withthe upper end of said time scale, means for guiding said sector throughthe slit when rotated, an alternating current timer motor, a drivingconnection between said motor and indicator including a slip frictionclutch and a mutilated gear whereby the indicator may be driven in adownscale direction at a rate corresponding to said time graduated scaleonly over the exposed range of movement of the indicator, manual meansfor rotating said indicator in either direction over its exposed rangeand over an additional completely hidden range, an alarm deviceenergized by said motor, a cam follower for controlling the operation ofsaid alarm, and a cam rotated with said indicator for actuating said camfollower to permit the operation of said alarm only when the indicatoris in approximately a zero time indicating position.

5. An elapsed time indicator comprising a stationary dial having acircular time graduated scale thereon extending over a substantialportion of a circle, and having a radial slit therein in radialalignment with the zero time graduation of such scale, an indicatorrotatively mounted behind the dial on an axis concentric with thecircular time scale, said indicator having a radial spider portion and asector-shaped indicator portion of a color contrasting with said dial,the sector portion being secured to the spider portion at one end onlyand with its free end extending in an upscale direction concentric withthe axis of rotation on a radius to permit it to pass through saidradial slit when the indicator is rotated, said indicator having a rangeof rotation from a position Where it is completely hidden behind thedial to a position where its free end is in radial alignment with theupper end of said time scale, means for guiding said sector through theslit when rotated, an alternating current timer motor, a drivingconnection between said motor and indicator including a slip frictionclutch and a mutilated gear whereby the indicator may be driven in adownscale direction at a rate corresponding to said time graduated scaleonly over the exposed range of movement of the indicator, manual meansfor rotating said indicator in either direction over its exposed rangeand over an additional completely hidden range, an alarm deviceenergized by said motor, a cam follower for controlling the operation ofsaid alarm, a cam rotated with said indicator for actuating said camfollower to permit the operation of said alarm only when the indicatoris in approximately a zero time indicating position, and means operatedin response to the manual rotation of said indicator in a downscaledirection beyond its zero time indicating position for deenergizing saidtimer motor.

HANS SPRINGER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,797,072 Caraba Mar. 17, 19312,389,908 Hickey Nov. 27, 1945 2,398,015 Leathers Apr. 9, 1946 FOREIGNPATENTS Number Country Date 592,442 Germany Mar. 26, 1932

